package com.byedu.commonutils;
import java.io.UnsupportedEncodingException;

/**
 * <p>Title:字符编码工具类 </p>
 * <p>Description:  </p>
 * <p>Copyright:  Copyright (c) 2007</p>
 * <p>Company:  </p>
 * @author:
 * @version 1.0
 */
public class CharTools {

    /**
     * 转换编码 ISO-8859-1到GB2312
     * @param text
     * @return
     */
    public static final String ISO2GB(String text) {
        String result = "";
        try {
            result = new String(text.getBytes("ISO-8859-1"), "GB2312");
        }
        catch (UnsupportedEncodingException ex) {
            result = ex.toString();
        }
        return result;
    }

    /**
     * 转换编码 GB2312到ISO-8859-1
     * @param text
     * @return
     */
    public static final String GB2ISO(String text) {
        String result = "";
        try {
            result = new String(text.getBytes("GB2312"), "ISO-8859-1");
        }
        catch (UnsupportedEncodingException ex) {
            ex.printStackTrace();
        }
        return result;
    }
    /**
     * Utf8URL编码
     * @param text
     * @return
     */
    public static final String Utf8URLencode(String text) {
        StringBuffer result = new StringBuffer();

        for (int i = 0; i < text.length(); i++) {

            char c = text.charAt(i);
            if (c >= 0 && c <= 255) {
                result.append(c);
            }else {

                byte[] b = new byte[0];
                try {
                    b = Character.toString(c).getBytes("UTF-8");
                }catch (Exception ex) {
                }

                for (int j = 0; j < b.length; j++) {
                    int k = b[j];
                    if (k < 0) k += 256;
                    result.append("%" + Integer.toHexString(k).toUpperCase());
                }

            }
        }

        return result.toString();
    }

    /**
     * Utf8URL解码
     * @param text
     * @return
     */
    public static final String Utf8URLdecode(String text) {
        String result = "";
        int p = 0;

        if (text!=null && text.length()>0){
            text = text.toLowerCase();
            p = text.indexOf("%e");
            if (p == -1) return text;

            while (p != -1) {
                result += text.substring(0, p);
                text = text.substring(p, text.length());
                if (text == "" || text.length() < 9) return result;

                result += CodeToWord(text.substring(0, 9));
                text = text.substring(9, text.length());
                p = text.indexOf("%e");
            }

        }

        return result + text;
    }

    /**
     * utf8URL编码转字符
     * @param text
     * @return
     */
    private static final String CodeToWord(String text) {
        String result;

        if (Utf8codeCheck(text)) {
            byte[] code = new byte[3];
            code[0] = (byte) (Integer.parseInt(text.substring(1, 3), 16) - 256);
            code[1] = (byte) (Integer.parseInt(text.substring(4, 6), 16) - 256);
            code[2] = (byte) (Integer.parseInt(text.substring(7, 9), 16) - 256);
            try {
                result = new String(code, "UTF-8");
            }catch (UnsupportedEncodingException ex) {
                result = null;
            }
        }
        else {
            result = text;
        }

        return result;
    }

    /**
     * 编码是否有效
     * @param text
     * @return
     */
    private static final boolean Utf8codeCheck(String text){
        String sign = "";
        if (text.startsWith("%e"))
            for (int i = 0, p = 0; p != -1; i++) {
                p = text.indexOf("%", p);
                if (p != -1)
                    p++;
                sign += p;
            }
        return sign.equals("147-1");
    }

    /**
     * 判断是否Utf8Url编码
     * @param text
     * @return
     */
    public static final boolean isUtf8Url(String text) {
        text = text.toLowerCase();
        int p = text.indexOf("%");
        if (p != -1 && text.length() - p > 9) {
            text = text.substring(p, p + 9);
        }
        return Utf8codeCheck(text);
    }

    /**
     * 测试
     * @param args
     */
    public static void main(String[] args) {

        //CharTools charTools = new CharTools();

        String url;

        url = "http://www.google.com/search?hl=zh-CN&newwindow=1&q=%E4%B8%AD%E5%9B%BD%E5%A4%A7%E7%99%BE%E7%A7%91%E5%9C%A8%E7%BA%BF%E5%85%A8%E6%96%87%E6%A3%80%E7%B4%A2&btnG=%E6%90%9C%E7%B4%A2&lr=";
        if(CharTools.isUtf8Url(url)){
            System.out.println(CharTools.Utf8URLdecode(url));
        }else{
            //System.out.println(URLDecoder.decode(url));
        }

        url = "http://www.baidu.com/baidu?word=%D6%D0%B9%FA%B4%F3%B0%D9%BF%C6%D4%DA%CF%DF%C8%AB%CE%C4%BC%EC%CB%F7&tn=myie2dg";
        if(CharTools.isUtf8Url(url)){
            System.out.println(CharTools.Utf8URLdecode(url));
        }else{
            //System.out.println(URLDecoder.decode(url));
        }

    }

}
